Hi
http://webu.co.uk/oligo/
"Oligo is a script that accepts two primers, a target sequence, salt
concentration and percent formamide and gives you the ranges where the
primers bind, Tm, %GC and length of the oligos, Ta, calculated
according to Breslauer et al 1986 and a list of six PCR programs that
you could try."
I wrote this optimum annealling temperature calculator that uses
nearest neighbour algorithm to calculate Tm of primers and product and
then works out the optimum temperature based on these values. Hope
you like it. The page includes references.
Jimi